Ethics, i.e. moral philosophy, is a rather big subject; there are many concepts within it, but if you don't understand it naturally, you'd probably respond better to an argument of practicality, as ErisDiscordia pointed out.

Anyway see here if you're interested; Walter's pointing out that, if you do not want someone else to force their political philosophy onto you, you shouldn't do the same; to do to others what you would not want to happen to you is immoral, for it is inconsistent and requires one group of people (even if it's just you) to have special rights over another, i.e. the state in microscopic view.